1. Field of the Invention
The present invention is related to the field of passive sonar, and more particularly to passive sonar systems adapted to provide target range and depth information.
2. Description of the Prior Art
Passive sonar systems, unlike active systems that can send out energy and await an echo return, must obtain range estimates based entirely on target radiated energy. Most passive sonar systems do not provide estimates of the range to targets that have been detected. Those systems that do provide estimates obtain time difference data either between largely separated array subsections or between complicated multipath signal structures. Thus, unless the sonar has a large aperture array or an extremely large computer to correlate multipath returns with all possible multipath structures, the estimate of range is not obtained.
It is, therefore, an object of the present system to provide a passive sonar system adapted to provide target and range information.
A further object of the invention is to provide a passive sonar system employing a relatively small sensor with limited computing power which is adapted to provide target range and depth information.
Yet another object of the present invention is to provide a simple range and depth estimation technique for mobile sonar systems.